Eaton worked with the U.S. General Services Administration and Delaware North Companies Parks and Resorts, which handles the majority of the park's transportation needs, in delivering four new Class 8 tractors with the Eaton diesel/electric hybrid systems to pull the visitor trams. An additional seven vehicles - 37-passenger shuttle buses - are on order and awaiting delivery.

Dan Anthonijsz, village garage manager at Yosemite, reports serious fuel-consumption reductions - now averaging about 6.7 mpg with the hybrid tram tractors compared to just 1 mpg with the propane-fueled trucks the new vehicles replaced.

Eaton has published a case study on the Yosemite project - publication number TRSL2517 - that's available for download here.